A unifying theme of the Program Project is the focus on cellular and molecular studies of the evolving microenvironment of airway inflammation. All three projects take advantage of genetic mouse models. Mycoplasma pulmonis infected mice as a model of chronic airway inflammation, and cutting-edge 2-photon and confocal imaging of cells and tissues in the ainways and lung. To this end, the mouse tools core, jointly administered by the co-directors, will serve the common needs of the projects by providing three main functions: (i) to standardize M. pulmonis preparation, infection procedures, and handling of infected mice;(ii) to develop, optimize and implement genotyping procedures for identifying mutant mice;and (iii) to develop and provide access to cutting edge methods for the real-time analysis of cells involved in the development of inflammation in the ainways and lung. First, the core staff will produce stocks of virulent M. pulmonis organisms, which will be tested for use in all experiments to ensure a consistent supply with minimal variability. Second, the core will use standardized flow cytometric, DNA preparation and polymerase chain reaction procedures to genotype mice from the mutant colonies that will be used in the three projects. Third, the core will provide access to and assist in novel and newly developed techniques for real-time viewing of living cells in the ainways and lung through a collaboration with the UCSF Biological Imaging Development Center (www.ucsf edu/bidc/). Centralizing and coordinating infection, genotyping procedures, and imaging approaches will avoid duplication of resources, ensure that standardized procedures are used by all groups, facilitate the exchange of information, and foster collaborative interactions.